Q:
A: what you wanna do is buy one can of 134a with uv dye in it, make sure the ac is turned on to it's max, when you inject the freon into the system the compressor should kick on, it will most likely keep cycling on and off, let it keep turning on and off until the can feels completely empty, the can will start to feel cold then it will start to warm up thats when the can is empty, after tou installed that can if the compressor did not kick on then you have either a bad sensor switch or bad fuse or an electrical problem, if you have an electrical problem have somebody experienced fix it, if these problems aint happening and the compressor is running ok then after 10 15 minutes check over the ac lines, condensor(thats the thing behind the radiator), compressor with a uv light or a black light the uv dye in the freon will be detectable under these lights find your leak fix it then have a professional vacuum the system down and refill it